This invention relates generally to paper making machines of the Fourdrinier type wherein the paper is formed on an essentially horizontal run of forming wire traveling from the breast roll to the couch roll. The invention is more specifically directed to a recent trend in Fourdrinier machines wherein a second wire is mounted on top of the primary wire downstream from the breast roll so that liquid is expressed from the stock on the primary wire through both wires. This type of combined machine is now commonly referred to as a "top former" machine, and as background for the description of the present invention, the best example of a top former machine is shown in Creagan et al U.S. Pat. No. 4,532,008 issued July 30, 1985 to the assignee of the present invention.